Severe Sleep Apnea ups Risk of Stroke, Cancer, Death

People with severe to moderate sleep apnea are at a higher risk of stroke, cancer and death than people without the disorder, according to a new study.

A 20-year follow-up study led by researchers at the University of Sydney in Australia, found that people with severe obstructive sleep apnea (OSA), a common type of sleep disorder caused by obstruction of upper airway, are at an increased risk of stroke, cancer and death. The risk association was constant even after considering certain factors such as BMI, smoking status, blood pressure and total cholesterol.

During the follow up study, the researchers saw that people with moderate to severe OSA were four times more likely to die. They also have a four-fold increased risk of having a stroke, three-fold increased risk of dying from cancer and are 2.5 times more prone to develop cancer.

"Sleep apnea is a common disease that has a powerful impact on public health because it greatly increases the risk of strokes, cancers and mortality from any cause," said lead author Nathaniel S. Marshall, PhD, senior lecturer in clinical trials at the University of Sydney in Australia.

The study was based on 397 adults who were a part of the ongoing Busselton Health Study.  The subjects' objective sleep data was collected in 1990 using a portable home sleep testing device.  Those with a history of stroke or cancer were not a part of the study.

The prevalence rate for moderate to severe OSA was 4.6 percent and for mild OSA it was 20.6 percent. During the follow up period, over 77 deaths and 31 strokes were reported. Apart from this, there were 125 cancer events that included 39 losses. Surprisingly, mild sleep apnea was not linked to any increased health risk.

"Obstructive sleep apnea is a chronic disease that can be destructive to your health," said American Academy of Sleep Medicine President Dr. Safwan Badr. "People with symptoms of sleep apnea, such as loud and frequent snoring or silent pauses in breathing during sleep, should see a board certified sleep medicine physician for a comprehensive sleep evaluation."

According to the American Academy of Sleep Medicine, OSA is a common sleep disorder and affects up to 7 percent of men and 5 percent of women. People with OSA experience repetitive episodes of complete or partial upper airway obstruction during sleep.  Continuous Positive Airway Pressure is the most effective treatment option for OSA.

The finding was documented in the journal of Clinical Sleep Medicine.